Fix stack update issue

Different type of resource with same name should consider to be a
new resource when stack-update.

Change-Id: I102ffbd1a1562c164f43969c87570096c280738a
Closes-Bug: #1404201

2 files changed, 29 insertions, 1 deletions

diff --git a/heat/engine/update.py b/heat/engine/update.py
index 4683223ca..67d4fda83 100644
--- a/heat/engine/update.py
+++ b/heat/engine/update.py
@@ -124,8 +124,10 @@ class StackUpdate(object):
     @scheduler.wrappertask
     def _process_new_resource_update(self, new_res):
         res_name = new_res.name
+        res_type = new_res.type()
 
-        if res_name in self.existing_stack:
+        if (res_name in self.existing_stack and
+                res_type == self.existing_stack[res_name].type()):
             existing_res = self.existing_stack[res_name]
             try:
                 yield self._update_in_place(existing_res,
diff --git a/heat/tests/test_stack_update.py b/heat/tests/test_stack_update.py
index 4867979d8..7be51c9c5 100644
--- a/heat/tests/test_stack_update.py
+++ b/heat/tests/test_stack_update.py
@@ -89,6 +89,32 @@ class StackUpdateTest(common.HeatTestCase):
                          self.stack.state)
         self.assertNotIn('BResource', self.stack)
 
+    def test_update_different_type(self):
+        tmpl = {'HeatTemplateFormatVersion': '2012-12-12',
+                'Resources': {
+                    'AResource': {'Type': 'GenericResourceType'}}}
+
+        self.stack = stack.Stack(self.ctx, 'update_test_stack',
+                                 template.Template(tmpl))
+        self.stack.store()
+        self.stack.create()
+        self.assertEqual((stack.Stack.CREATE, stack.Stack.COMPLETE),
+                         self.stack.state)
+        self.assertEqual('GenericResourceType',
+                         self.stack['AResource'].type())
+
+        tmpl2 = {'HeatTemplateFormatVersion': '2012-12-12',
+                 'Resources': {'AResource': {'Type': 'ResourceWithPropsType',
+                                             'Properties': {'Foo': 'abc'}}}}
+
+        updated_stack = stack.Stack(self.ctx, 'updated_stack',
+                                    template.Template(tmpl2))
+        self.stack.update(updated_stack)
+        self.assertEqual((stack.Stack.UPDATE, stack.Stack.COMPLETE),
+                         self.stack.state)
+        self.assertEqual('ResourceWithPropsType',
+                         self.stack['AResource'].type())
+
     def test_update_description(self):
         tmpl = {'HeatTemplateFormatVersion': '2012-12-12',
                 'Description': 'ATemplate',